In the related field, the refractory protection layer at the bottom of the metallurgical furnace is usually built with refractory bricks, which are locked mutually to avoid the phenomenon of “floating bricks” in the smelting process. However, the refractory protection layer of the metallurgical furnace in some situations, especially at the furnace bottom (especially the round bottom), has poor anti-permeability and anti-erosion property because there are still joints between the refractory bricks. The high temperature metal in the furnace will penetrate into the housing of furnace bottom and will damage the housing, which affects the service life and usage of the metallurgical furnace.